Express your answer in scientific notation. $4.9\cdot 10^{5} - 5.8 \cdot 10^{4} = $
Solution: $\phantom{=}{ 4.9\cdot 10^{5}} - 5.8 \cdot 10^{4}$ $={49\cdot 10^{4}} - 5.8 \cdot 10^{4}$ $= (49-5.8)\cdot10^{4}$ $=43.2\cdot10^{4}$ $=4.32\cdot10^{5}$